Design of SAW Oscillators

Abstract

The design and measurement of a monolithic low jitter surface acoustic wave (SAW) based oscillator employing an integrated micro-electromechanical systems (MEMS) SAW resonator developed on top of a standard 0.13µm CMOS technology are presented. All oscillator circuitry is placed under the SAW resonator for efficient area utilization enabling a compact low cost highly integrated solution. The oscillator has an oscillation frequency in ranges of 300 MHz and power dissipation of 10.5 mW. Measured phase noise performance of the oscillator is -121 dBc/Hz at 10 kHz offset frequency and measured noise floor is a -146 dBc/Hz. The integrated phase jitter from 12 kHz to 20 MHz is less than 160 fs. For a lower power consumption of 5 mW, the phase noise performance is -118 dBc/Hz at 10 kHz offset frequency, -142 dBc/Hz noise oor, and the integrated phase jitter is 212 fs. This performance allows the development of high performance low jitter highly integrated low cost clocking solutions based on MEMS SAW oscillators replacing traditional quartz crystal and SAW based discrete solutions.